btrfs: read number of data stripes from map only once

There are several places that call nr_data_stripes, but this value does
not change.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2019-05-17 11:43:45 +02:00
parent 72ad813157
commit cff8267228
2 changed files with 13 additions and 12 deletions

View File

@ -2660,18 +2660,18 @@ static int get_raid56_logic_offset(u64 physical, int num,
u64 last_offset;
u32 stripe_index;
u32 rot;
const int data_stripes = nr_data_stripes(map);
last_offset = (physical - map->stripes[num].physical) *
nr_data_stripes(map);
last_offset = (physical - map->stripes[num].physical) * data_stripes;
if (stripe_start)
*stripe_start = last_offset;
*offset = last_offset;
for (i = 0; i < nr_data_stripes(map); i++) {
for (i = 0; i < data_stripes; i++) {
*offset = last_offset + i * map->stripe_len;
stripe_nr = div64_u64(*offset, map->stripe_len);
stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
stripe_nr = div_u64(stripe_nr, data_stripes);
/* Work out the disk rotation on this stripe-set */
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);

View File

@ -5918,6 +5918,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
u64 stripe_nr;
u64 stripe_len;
u32 stripe_index;
int data_stripes;
int i;
int ret = 0;
int num_stripes;
@ -5949,6 +5950,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
* to get to this block
*/
stripe_nr = div64_u64(stripe_nr, stripe_len);
data_stripes = nr_data_stripes(map);
stripe_offset = stripe_nr * stripe_len;
if (offset < stripe_offset) {
@ -5965,7 +5967,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
/* if we're here for raid56, we need to know the stripe aligned start */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
unsigned long full_stripe_len = stripe_len * data_stripes;
raid56_full_stripe_start = offset;
/* allow a write of a full stripe, but make sure we don't
@ -5983,7 +5985,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
stripe (on a single disk). */
if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
(op == BTRFS_MAP_WRITE)) {
max_len = stripe_len * nr_data_stripes(map) -
max_len = stripe_len * data_stripes -
(offset - raid56_full_stripe_start);
} else {
/* we limit the length of each bio to what fits in a stripe */
@ -6073,7 +6075,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
/* push stripe_nr back to the start of the full stripe */
stripe_nr = div64_u64(raid56_full_stripe_start,
stripe_len * nr_data_stripes(map));
stripe_len * data_stripes);
/* RAID[56] write or recovery. Return all stripes */
num_stripes = map->num_stripes;
@ -6089,10 +6091,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
* Mirror #3 is RAID6 Q block.
*/
stripe_nr = div_u64_rem(stripe_nr,
nr_data_stripes(map), &stripe_index);
data_stripes, &stripe_index);
if (mirror_num > 1)
stripe_index = nr_data_stripes(map) +
mirror_num - 2;
stripe_index = data_stripes + mirror_num - 2;
/* We distribute the parity blocks across stripes */
div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
@ -6150,8 +6151,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
div_u64_rem(stripe_nr, num_stripes, &rot);
/* Fill in the logical address of each stripe */
tmp = stripe_nr * nr_data_stripes(map);
for (i = 0; i < nr_data_stripes(map); i++)
tmp = stripe_nr * data_stripes;
for (i = 0; i < data_stripes; i++)
bbio->raid_map[(i+rot) % num_stripes] =
em->start + (tmp + i) * map->stripe_len;